/* * GRE over IPv6 protocol decoder. * * Authors: Dmitry Kozlov (xeb@mail.ru) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static bool log_ecn_error = true; module_param(log_ecn_error, bool, 0644); MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); #define IP6_GRE_HASH_SIZE_SHIFT 5 #define IP6_GRE_HASH_SIZE (1 << IP6_GRE_HASH_SIZE_SHIFT) static unsigned int ip6gre_net_id __read_mostly; struct ip6gre_net { struct ip6_tnl __rcu *tunnels[4][IP6_GRE_HASH_SIZE]; struct net_device *fb_tunnel_dev; }; static struct rtnl_link_ops ip6gre_link_ops __read_mostly; static struct rtnl_link_ops ip6gre_tap_ops __read_mostly; static int ip6gre_tunnel_init(struct net_device *dev); static void ip6gre_tunnel_setup(struct net_device *dev); static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t); static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu); /* Tunnel hash table */ /* 4 hash tables: 3: (remote,local) 2: (remote,*) 1: (*,local) 0: (*,*) We require exact key match i.e. if a key is present in packet it will match only tunnel with the same key; if it is not present, it will match only keyless tunnel. All keysless packets, if not matched configured keyless tunnels will match fallback tunnel. */ #define HASH_KEY(key) (((__force u32)key^((__force u32)key>>4))&(IP6_GRE_HASH_SIZE - 1)) static u32 HASH_ADDR(const struct in6_addr *addr) { u32 hash = ipv6_addr_hash(addr); return hash_32(hash, IP6_GRE_HASH_SIZE_SHIFT); } #define tunnels_r_l tunnels[3] #define tunnels_r tunnels[2] #define tunnels_l tunnels[1] #define tunnels_wc tunnels[0] /* Given src, dst and key, find appropriate for input tunnel. */ static struct ip6_tnl *ip6gre_tunnel_lookup(struct net_device *dev, const struct in6_addr *remote, const struct in6_addr *local, __be32 key, __be16 gre_proto) { struct net *net = dev_net(dev); int link = dev->ifindex; unsigned int h0 = HASH_ADDR(remote); unsigned int h1 = HASH_KEY(key); struct ip6_tnl *t, *cand = NULL; struct ip6gre_net *ign = net_generic(net, ip6gre_net_id); int dev_type = (gre_proto == htons(ETH_P_TEB)) ? ARPHRD_ETHER : ARPHRD_IP6GRE; int score, cand_score = 4; for_each_ip_tunnel_rcu(t, ign->tunnels_r_l[h0 ^ h1]) { if (!ipv6_addr_equal(local, &t->parms.laddr) || !ipv6_addr_equal(remote, &t->parms.raddr) || key != t->parms.i_key || !(t->dev->flags & IFF_UP)) continue; if (t->dev->type != ARPHRD_IP6GRE && t->dev->type != dev_type) continue; score = 0; if (t->parms.link != link) score |= 1; if (t->dev->type != dev_type) score |= 2; if (score == 0) return t; if (score < cand_score) { cand = t; cand_score = score; } } for_each_ip_tunnel_rcu(t, ign->tunnels_r[h0 ^ h1]) { if (!ipv6_addr_equal(remote, &t->parms.raddr) || key != t->parms.i_key || !(t->dev->flags & IFF_UP)) continue; if (t->dev->type != ARPHRD_IP6GRE && t->dev->type != dev_type) continue; score = 0; if (t->parms.link != link) score |= 1; if (t->dev->type != dev_type) score |= 2; if (score == 0) return t; if (score < cand_score) { cand = t; cand_score = score; } } for_each_ip_tunnel_rcu(t, ign->tunnels_l[h1]) { if ((!ipv6_addr_equal(local, &t->parms.laddr) && (!ipv6_addr_equal(local, &t->parms.raddr) || !ipv6_addr_is_multicast(local))) || key != t->parms.i_key || !(t->dev->flags & IFF_UP)) continue; if (t->dev->type != ARPHRD_IP6GRE && t->dev->type != dev_type) continue; score = 0; if (t->parms.link != link) score |= 1; if (t->dev->type != dev_type) score |= 2; if (score == 0) return t; if (score < cand_score) { cand = t; cand_score = score; } } for_each_ip_tunnel_rcu(t, ign->tunnels_wc[h1]) { if (t->parms.i_key != key || !(t->dev->flags & IFF_UP)) continue; if (t->dev->type != ARPHRD_IP6GRE && t->dev->type != dev_type) continue; score = 0; if (t->parms.link != link) score |= 1; if (t->dev->type != dev_type) score |= 2; if (score == 0) return t; if (score < cand_score) { cand = t; cand_score = score; } } if (cand) return cand; dev = ign->fb_tunnel_dev; if (dev->flags & IFF_UP) return netdev_priv(dev); return NULL; } static struct ip6_tnl __rcu **__ip6gre_bucket(struct ip6gre_net *ign, const struct __ip6_tnl_parm *p) { const struct in6_addr *remote = &p->raddr; const struct in6_addr *local = &p->laddr; unsigned int h = HASH_KEY(p->i_key); int prio = 0; if (!ipv6_addr_any(local)) prio |= 1; if (!ipv6_addr_any(remote) && !ipv6_addr_is_multicast(remote)) { prio |= 2; h ^= HASH_ADDR(remote); } return &ign->tunnels[prio][h]; } static inline struct ip6_tnl __rcu **ip6gre_bucket(struct ip6gre_net *ign, const struct ip6_tnl *t) { return __ip6gre_bucket(ign, &t->parms); } static void ip6gre_tunnel_link(struct ip6gre_net *ign, struct ip6_tnl *t) { struct ip6_tnl __rcu **tp = ip6gre_bucket(ign, t); rcu_assign_pointer(t->next, rtnl_dereference(*tp)); rcu_assign_pointer(*tp, t); } static void ip6gre_tunnel_unlink(struct ip6gre_net *ign, struct ip6_tnl *t) { struct ip6_tnl __rcu **tp; struct ip6_tnl *iter; for (tp = ip6gre_bucket(ign, t); (iter = rtnl_dereference(*tp)) != NULL; tp = &iter->next) { if (t == iter) { rcu_assign_pointer(*tp, t->next); break; } } } static struct ip6_tnl *ip6gre_tunnel_find(struct net *net, const struct __ip6_tnl_parm *parms, int type) { const struct in6_addr *remote = &parms->raddr; const struct in6_addr *local = &parms->laddr; __be32 key = parms->i_key; int link = parms->link; struct ip6_tnl *t; struct ip6_tnl __rcu **tp; struct ip6gre_net *ign = net_generic(net, ip6gre_net_id); for (tp = __ip6gre_bucket(ign, parms); (t = rtnl_dereference(*tp)) != NULL; tp = &t->next) if (ipv6_addr_equal(local, &t->parms.laddr) && ipv6_addr_equal(remote, &t->parms.raddr) && key == t->parms.i_key && link == t->parms.link && type == t->dev->type) break; return t; } static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net, const struct __ip6_tnl_parm *parms, int create) { struct ip6_tnl *t, *nt; struct net_device *dev; char name[IFNAMSIZ]; struct ip6gre_net *ign = net_generic(net, ip6gre_net_id); t = ip6gre_tunnel_find(net, parms, ARPHRD_IP6GRE); if (t && create) return NULL; if (t || !create) return t; if (parms->name[0]) strlcpy(name, parms->name, IFNAMSIZ); else strcpy(name, "ip6gre%d"); dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, ip6gre_tunnel_setup); if (!dev) return NULL; dev_net_set(dev, net); nt = netdev_priv(dev); nt->parms = *parms; dev->rtnl_link_ops = &ip6gre_link_ops; nt->dev = dev; nt->net = dev_net(dev); ip6gre_tnl_link_config(nt, 1); if (register_netdevice(dev) < 0) goto failed_free; /* Can use a lockless transmit, unless we generate output sequences */ if (!(nt->parms.o_flags & TUNNEL_SEQ)) dev->features |= NETIF_F_LLTX; dev_hold(dev); ip6gre_tunnel_link(ign, nt); return nt; failed_free: free_netdev(dev); return NULL; } static void ip6gre_tunnel_uninit(struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id); ip6gre_tunnel_unlink(ign, t); dst_cache_reset(&t->dst_cache); dev_put(dev); } static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt, u8 type, u8 code, int offset, __be32 info) { const struct gre_base_hdr *greh; const struct ipv6hdr *ipv6h; int grehlen = sizeof(*greh); struct ip6_tnl *t; int key_off = 0; __be16 flags; __be32 key; if (!pskb_may_pull(skb, offset + grehlen)) return; greh = (const struct gre_base_hdr *)(skb->data + offset); flags = greh->flags; if (flags & (GRE_VERSION | GRE_ROUTING)) return; if (flags & GRE_CSUM) grehlen += 4; if (flags & GRE_KEY) { key_off = grehlen + offset; grehlen += 4; } if (!pskb_may_pull(skb, offset + grehlen)) return; ipv6h = (const struct ipv6hdr *)skb->data; greh = (const struct gre_base_hdr *)(skb->data + offset); key = key_off ? *(__be32 *)(skb->data + key_off) : 0; t = ip6gre_tunnel_lookup(skb->dev, &ipv6h->daddr, &ipv6h->saddr, key, greh->protocol); if (!t) return; switch (type) { __u32 teli; struct ipv6_tlv_tnl_enc_lim *tel; __u32 mtu; case ICMPV6_DEST_UNREACH: net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n", t->parms.name); break; case ICMPV6_TIME_EXCEED: if (code == ICMPV6_EXC_HOPLIMIT) { net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n", t->parms.name); } break; case ICMPV6_PARAMPROB: teli = 0; if (code == ICMPV6_HDR_FIELD) teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data); if (teli && teli == be32_to_cpu(info) - 2) { tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; if (tel->encap_limit == 0) { net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n", t->parms.name); } } else { net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n", t->parms.name); } break; case ICMPV6_PKT_TOOBIG: mtu = be32_to_cpu(info) - offset; if (mtu < IPV6_MIN_MTU) mtu = IPV6_MIN_MTU; t->dev->mtu = mtu; break; } if (time_before(jiffies, t->err_time + IP6TUNNEL_ERR_TIMEO)) t->err_count++; else t->err_count = 1; t->err_time = jiffies; } static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi) { const struct ipv6hdr *ipv6h; struct ip6_tnl *tunnel; ipv6h = ipv6_hdr(skb); tunnel = ip6gre_tunnel_lookup(skb->dev, &ipv6h->saddr, &ipv6h->daddr, tpi->key, tpi->proto); if (tunnel) { ip6_tnl_rcv(tunnel, skb, tpi, NULL, false); return PACKET_RCVD; } return PACKET_REJECT; } static int gre_rcv(struct sk_buff *skb) { struct tnl_ptk_info tpi; bool csum_err = false; int hdr_len; hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IPV6), 0); if (hdr_len < 0) goto drop; if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false)) goto drop; if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD) return 0; icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0); drop: kfree_skb(skb); return 0; } static int gre_handle_offloads(struct sk_buff *skb, bool csum) { return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE); } static netdev_tx_t __gre6_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield, struct flowi6 *fl6, int encap_limit, __u32 *pmtu, __be16 proto) { struct ip6_tnl *tunnel = netdev_priv(dev); __be16 protocol = (dev->type == ARPHRD_ETHER) ? htons(ETH_P_TEB) : proto; if (dev->type == ARPHRD_ETHER) IPCB(skb)->flags = 0; if (dev->header_ops && dev->type == ARPHRD_IP6GRE) fl6->daddr = ((struct ipv6hdr *)skb->data)->daddr; else fl6->daddr = tunnel->parms.raddr; if (tunnel->parms.o_flags & TUNNEL_SEQ) tunnel->o_seqno++; /* Push GRE header. */ gre_build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags, protocol, tunnel->parms.o_key, htonl(tunnel->o_seqno)); return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu, NEXTHDR_GRE); } static inline int ip6gre_xmit_ipv4(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); const struct iphdr *iph = ip_hdr(skb); int encap_limit = -1; struct flowi6 fl6; __u8 dsfield; __u32 mtu; int err; memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) encap_limit = t->parms.encap_limit; memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6)); if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) dsfield = ipv4_get_dsfield(iph); else dsfield = ip6_tclass(t->parms.flowinfo); if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) fl6.flowi6_mark = skb->mark; else fl6.flowi6_mark = t->parms.fwmark; fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL); err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)); if (err) return -1; err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu, skb->protocol); if (err != 0) { /* XXX: send ICMP error even if DF is not set. */ if (err == -EMSGSIZE) icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); return -1; } return 0; } static inline int ip6gre_xmit_ipv6(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); struct ipv6hdr *ipv6h = ipv6_hdr(skb); int encap_limit = -1; __u16 offset; struct flowi6 fl6; __u8 dsfield; __u32 mtu; int err; if (ipv6_addr_equal(&t->parms.raddr, &ipv6h->saddr)) return -1; offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb)); /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */ ipv6h = ipv6_hdr(skb); if (offset > 0) { struct ipv6_tlv_tnl_enc_lim *tel; tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset]; if (tel->encap_limit == 0) { icmpv6_send(skb, ICMPV6_PARAMPROB, ICMPV6_HDR_FIELD, offset + 2); return -1; } encap_limit = tel->encap_limit - 1; } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) encap_limit = t->parms.encap_limit; memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6)); if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) dsfield = ipv6_get_dsfield(ipv6h); else dsfield = ip6_tclass(t->parms.flowinfo); if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL) fl6.flowlabel |= ip6_flowlabel(ipv6h); if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) fl6.flowi6_mark = skb->mark; else fl6.flowi6_mark = t->parms.fwmark; fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL); if (gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM))) return -1; err = __gre6_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu, skb->protocol); if (err != 0) { if (err == -EMSGSIZE) icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); return -1; } return 0; } /** * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own * @t: the outgoing tunnel device * @hdr: IPv6 header from the incoming packet * * Description: * Avoid trivial tunneling loop by checking that tunnel exit-point * doesn't match source of incoming packet. * * Return: * 1 if conflict, * 0 else **/ static inline bool ip6gre_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr) { return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); } static int ip6gre_xmit_other(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); int encap_limit = -1; struct flowi6 fl6; __u32 mtu; int err; if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) encap_limit = t->parms.encap_limit; memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6)); err = gre_handle_offloads(skb, !!(t->parms.o_flags & TUNNEL_CSUM)); if (err) return err; err = __gre6_xmit(skb, dev, 0, &fl6, encap_limit, &mtu, skb->protocol); return err; } static netdev_tx_t ip6gre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); struct net_device_stats *stats = &t->dev->stats; int ret; if (!ip6_tnl_xmit_ctl(t, &t->parms.laddr, &t->parms.raddr)) goto tx_err; switch (skb->protocol) { case htons(ETH_P_IP): ret = ip6gre_xmit_ipv4(skb, dev); break; case htons(ETH_P_IPV6): ret = ip6gre_xmit_ipv6(skb, dev); break; default: ret = ip6gre_xmit_other(skb, dev); break; } if (ret < 0) goto tx_err; return NETDEV_TX_OK; tx_err: stats->tx_errors++; stats->tx_dropped++; kfree_skb(skb); return NETDEV_TX_OK; } static void ip6gre_tnl_link_config(struct ip6_tnl *t, int set_mtu) { struct net_device *dev = t->dev; struct __ip6_tnl_parm *p = &t->parms; struct flowi6 *fl6 = &t->fl.u.ip6; int t_hlen; if (dev->type != ARPHRD_ETHER) { memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); } /* Set up flowi template */ fl6->saddr = p->laddr; fl6->daddr = p->raddr; fl6->flowi6_oif = p->link; fl6->flowlabel = 0; fl6->flowi6_proto = IPPROTO_GRE; if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET); p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr); if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV && dev->type != ARPHRD_ETHER) dev->flags |= IFF_POINTOPOINT; else dev->flags &= ~IFF_POINTOPOINT; t->tun_hlen = gre_calc_hlen(t->parms.o_flags); t->hlen = t->encap_hlen + t->tun_hlen; t_hlen = t->hlen + sizeof(struct ipv6hdr); if (p->flags & IP6_TNL_F_CAP_XMIT) { int strict = (ipv6_addr_type(&p->raddr) & (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)); struct rt6_info *rt = rt6_lookup(t->net, &p->raddr, &p->laddr, p->link, strict); if (!rt) return; if (rt->dst.dev) { dev->hard_header_len = rt->dst.dev->hard_header_len + t_hlen; if (set_mtu) { dev->mtu = rt->dst.dev->mtu - t_hlen; if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) dev->mtu -= 8; if (dev->type == ARPHRD_ETHER) dev->mtu -= ETH_HLEN; if (dev->mtu < IPV6_MIN_MTU) dev->mtu = IPV6_MIN_MTU; } } ip6_rt_put(rt); } } static int ip6gre_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p, int set_mtu) { t->parms.laddr = p->laddr; t->parms.raddr = p->raddr; t->parms.flags = p->flags; t->parms.hop_limit = p->hop_limit; t->parms.encap_limit = p->encap_limit; t->parms.flowinfo = p->flowinfo; t->parms.link = p->link; t->parms.proto = p->proto; t->parms.i_key = p->i_key; t->parms.o_key = p->o_key; t->parms.i_flags = p->i_flags; t->parms.o_flags = p->o_flags; t->parms.fwmark = p->fwmark; dst_cache_reset(&t->dst_cache); ip6gre_tnl_link_config(t, set_mtu); return 0; } static void ip6gre_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u) { p->laddr = u->laddr; p->raddr = u->raddr; p->flags = u->flags; p->hop_limit = u->hop_limit; p->encap_limit = u->encap_limit; p->flowinfo = u->flowinfo; p->link = u->link; p->i_key = u->i_key; p->o_key = u->o_key; p->i_flags = gre_flags_to_tnl_flags(u->i_flags); p->o_flags = gre_flags_to_tnl_flags(u->o_flags); memcpy(p->name, u->name, sizeof(u->name)); } static void ip6gre_tnl_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p) { u->proto = IPPROTO_GRE; u->laddr = p->laddr; u->raddr = p->raddr; u->flags = p->flags; u->hop_limit = p->hop_limit; u->encap_limit = p->encap_limit; u->flowinfo = p->flowinfo; u->link = p->link; u->i_key = p->i_key; u->o_key = p->o_key; u->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags); u->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags); memcpy(u->name, p->name, sizeof(u->name)); } static int ip6gre_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) { int err = 0; struct ip6_tnl_parm2 p; struct __ip6_tnl_parm p1; struct ip6_tnl *t = netdev_priv(dev); struct net *net = t->net; struct ip6gre_net *ign = net_generic(net, ip6gre_net_id); memset(&p1, 0, sizeof(p1)); switch (cmd) { case SIOCGETTUNNEL: if (dev == ign->fb_tunnel_dev) { if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { err = -EFAULT; break; } ip6gre_tnl_parm_from_user(&p1, &p); t = ip6gre_tunnel_locate(net, &p1, 0); if (!t) t = netdev_priv(dev); } memset(&p, 0, sizeof(p)); ip6gre_tnl_parm_to_user(&p, &t->parms); if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) err = -EFAULT; break; case SIOCADDTUNNEL: case SIOCCHGTUNNEL: err = -EPERM; if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) goto done; err = -EFAULT; if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) goto done; err = -EINVAL; if ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)) goto done; if (!(p.i_flags&GRE_KEY)) p.i_key = 0; if (!(p.o_flags&GRE_KEY)) p.o_key = 0; ip6gre_tnl_parm_from_user(&p1, &p); t = ip6gre_tunnel_locate(net, &p1, cmd == SIOCADDTUNNEL); if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { if (t) { if (t->dev != dev) { err = -EEXIST; break; } } else { t = netdev_priv(dev); ip6gre_tunnel_unlink(ign, t); synchronize_net(); ip6gre_tnl_change(t, &p1, 1); ip6gre_tunnel_link(ign, t); netdev_state_change(dev); } } if (t) { err = 0; memset(&p, 0, sizeof(p)); ip6gre_tnl_parm_to_user(&p, &t->parms); if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) err = -EFAULT; } else err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); break; case SIOCDELTUNNEL: err = -EPERM; if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) goto done; if (dev == ign->fb_tunnel_dev) { err = -EFAULT; if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) goto done; err = -ENOENT; ip6gre_tnl_parm_from_user(&p1, &p); t = ip6gre_tunnel_locate(net, &p1, 0); if (!t) goto done; err = -EPERM; if (t == netdev_priv(ign->fb_tunnel_dev)) goto done; dev = t->dev; } unregister_netdevice(dev); err = 0; break; default: err = -EINVAL; } done: return err; } static int ip6gre_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, const void *daddr, const void *saddr, unsigned int len) { struct ip6_tnl *t = netdev_priv(dev); struct ipv6hdr *ipv6h = skb_push(skb, t->hlen); __be16 *p = (__be16 *)(ipv6h+1); ip6_flow_hdr(ipv6h, 0, ip6_make_flowlabel(dev_net(dev), skb, t->fl.u.ip6.flowlabel, true, &t->fl.u.ip6)); ipv6h->hop_limit = t->parms.hop_limit; ipv6h->nexthdr = NEXTHDR_GRE; ipv6h->saddr = t->parms.laddr; ipv6h->daddr = t->parms.raddr; p[0] = t->parms.o_flags; p[1] = htons(type); /* * Set the source hardware address. */ if (saddr) memcpy(&ipv6h->saddr, saddr, sizeof(struct in6_addr)); if (daddr) memcpy(&ipv6h->daddr, daddr, sizeof(struct in6_addr)); if (!ipv6_addr_any(&ipv6h->daddr)) return t->hlen; return -t->hlen; } static const struct header_ops ip6gre_header_ops = { .create = ip6gre_header, }; static const struct net_device_ops ip6gre_netdev_ops = { .ndo_init = ip6gre_tunnel_init, .ndo_uninit = ip6gre_tunnel_uninit, .ndo_start_xmit = ip6gre_tunnel_xmit, .ndo_do_ioctl = ip6gre_tunnel_ioctl, .ndo_change_mtu = ip6_tnl_change_mtu, .ndo_get_stats64 = ip_tunnel_get_stats64, .ndo_get_iflink = ip6_tnl_get_iflink, }; static void ip6gre_dev_free(struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); dst_cache_destroy(&t->dst_cache); free_percpu(dev->tstats); } static void ip6gre_tunnel_setup(struct net_device *dev) { dev->netdev_ops = &ip6gre_netdev_ops; dev->needs_free_netdev = true; dev->priv_destructor = ip6gre_dev_free; dev->type = ARPHRD_IP6GRE; dev->flags |= IFF_NOARP; dev->addr_len = sizeof(struct in6_addr); netif_keep_dst(dev); /* This perm addr will be used as interface identifier by IPv6 */ dev->addr_assign_type = NET_ADDR_RANDOM; eth_random_addr(dev->perm_addr); } static int ip6gre_tunnel_init_common(struct net_device *dev) { struct ip6_tnl *tunnel; int ret; int t_hlen; tunnel = netdev_priv(dev); tunnel->dev = dev; tunnel->net = dev_net(dev); strcpy(tunnel->parms.name, dev->name); dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); if (!dev->tstats) return -ENOMEM; ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL); if (ret) { free_percpu(dev->tstats); dev->tstats = NULL; return ret; } tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags); tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen; t_hlen = tunnel->hlen + sizeof(struct ipv6hdr); dev->hard_header_len = LL_MAX_HEADER + t_hlen; dev->mtu = ETH_DATA_LEN - t_hlen; if (dev->type == ARPHRD_ETHER) dev->mtu -= ETH_HLEN; if (!(tunnel->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) dev->mtu -= 8; return 0; } static int ip6gre_tunnel_init(struct net_device *dev) { struct ip6_tnl *tunnel; int ret; ret = ip6gre_tunnel_init_common(dev); if (ret) return ret; tunnel = netdev_priv(dev); memcpy(dev->dev_addr, &tunnel->parms.laddr, sizeof(struct in6_addr)); memcpy(dev->broadcast, &tunnel->parms.raddr, sizeof(struct in6_addr)); if (ipv6_addr_any(&tunnel->parms.raddr)) dev->header_ops = &ip6gre_header_ops; return 0; } static void ip6gre_fb_tunnel_init(struct net_device *dev) { struct ip6_tnl *tunnel = netdev_priv(dev); tunnel->dev = dev; tunnel->net = dev_net(dev); strcpy(tunnel->parms.name, dev->name); tunnel->hlen = sizeof(struct ipv6hdr) + 4; dev_hold(dev); } static struct inet6_protocol ip6gre_protocol __read_mostly = { .handler = gre_rcv, .err_handler = ip6gre_err, .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, }; static void ip6gre_destroy_tunnels(struct net *net, struct list_head *head) { struct ip6gre_net *ign = net_generic(net, ip6gre_net_id); struct net_device *dev, *aux; int prio; for_each_netdev_safe(net, dev, aux) if (dev->rtnl_link_ops == &ip6gre_link_ops || dev->rtnl_link_ops == &ip6gre_tap_ops) unregister_netdevice_queue(dev, head); for (prio = 0; prio < 4; prio++) { int h; for (h = 0; h < IP6_GRE_HASH_SIZE; h++) { struct ip6_tnl *t; t = rtnl_dereference(ign->tunnels[prio][h]); while (t) { /* If dev is in the same netns, it has already * been added to the list by the previous loop. */ if (!net_eq(dev_net(t->dev), net)) unregister_netdevice_queue(t->dev, head); t = rtnl_dereference(t->next); } } } } static int __net_init ip6gre_init_net(struct net *net) { struct ip6gre_net *ign = net_generic(net, ip6gre_net_id); int err; ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6gre0", NET_NAME_UNKNOWN, ip6gre_tunnel_setup); if (!ign->fb_tunnel_dev) { err = -ENOMEM; goto err_alloc_dev; } dev_net_set(ign->fb_tunnel_dev, net); /* FB netdevice is special: we have one, and only one per netns. * Allowing to move it to another netns is clearly unsafe. */ ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; ip6gre_fb_tunnel_init(ign->fb_tunnel_dev); ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops; err = register_netdev(ign->fb_tunnel_dev); if (err) goto err_reg_dev; rcu_assign_pointer(ign->tunnels_wc[0], netdev_priv(ign->fb_tunnel_dev)); return 0; err_reg_dev: free_netdev(ign->fb_tunnel_dev); err_alloc_dev: return err; } static void __net_exit ip6gre_exit_net(struct net *net) { LIST_HEAD(list); rtnl_lock(); ip6gre_destroy_tunnels(net, &list); unregister_netdevice_many(&list); rtnl_unlock(); } static struct pernet_operations ip6gre_net_ops = { .init = ip6gre_init_net, .exit = ip6gre_exit_net, .id = &ip6gre_net_id, .size = sizeof(struct ip6gre_net), }; static int ip6gre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[]) { __be16 flags; if (!data) return 0; flags = 0; if (data[IFLA_GRE_IFLAGS]) flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]); if (data[IFLA_GRE_OFLAGS]) flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]); if (flags & (GRE_VERSION|GRE_ROUTING)) return -EINVAL; return 0; } static int ip6gre_tap_validate(struct nlattr *tb[], struct nlattr *data[]) { struct in6_addr daddr; if (tb[IFLA_ADDRESS]) { if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) return -EINVAL; if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) return -EADDRNOTAVAIL; } if (!data) goto out; if (data[IFLA_GRE_REMOTE]) { daddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]); if (ipv6_addr_any(&daddr)) return -EINVAL; } out: return ip6gre_tunnel_validate(tb, data); } static void ip6gre_netlink_parms(struct nlattr *data[], struct __ip6_tnl_parm *parms) { memset(parms, 0, sizeof(*parms)); if (!data) return; if (data[IFLA_GRE_LINK]) parms->link = nla_get_u32(data[IFLA_GRE_LINK]); if (data[IFLA_GRE_IFLAGS]) parms->i_flags = gre_flags_to_tnl_flags( nla_get_be16(data[IFLA_GRE_IFLAGS])); if (data[IFLA_GRE_OFLAGS]) parms->o_flags = gre_flags_to_tnl_flags( nla_get_be16(data[IFLA_GRE_OFLAGS])); if (data[IFLA_GRE_IKEY]) parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]); if (data[IFLA_GRE_OKEY]) parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]); if (data[IFLA_GRE_LOCAL]) parms->laddr = nla_get_in6_addr(data[IFLA_GRE_LOCAL]); if (data[IFLA_GRE_REMOTE]) parms->raddr = nla_get_in6_addr(data[IFLA_GRE_REMOTE]); if (data[IFLA_GRE_TTL]) parms->hop_limit = nla_get_u8(data[IFLA_GRE_TTL]); if (data[IFLA_GRE_ENCAP_LIMIT]) parms->encap_limit = nla_get_u8(data[IFLA_GRE_ENCAP_LIMIT]); if (data[IFLA_GRE_FLOWINFO]) parms->flowinfo = nla_get_be32(data[IFLA_GRE_FLOWINFO]); if (data[IFLA_GRE_FLAGS]) parms->flags = nla_get_u32(data[IFLA_GRE_FLAGS]); if (data[IFLA_GRE_FWMARK]) parms->fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]); } static int ip6gre_tap_init(struct net_device *dev) { struct ip6_tnl *tunnel; int ret; ret = ip6gre_tunnel_init_common(dev); if (ret) return ret; dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; tunnel = netdev_priv(dev); ip6gre_tnl_link_config(tunnel, 1); return 0; } static const struct net_device_ops ip6gre_tap_netdev_ops = { .ndo_init = ip6gre_tap_init, .ndo_uninit = ip6gre_tunnel_uninit, .ndo_start_xmit = ip6gre_tunnel_xmit, .ndo_set_mac_address = eth_mac_addr, .ndo_validate_addr = eth_validate_addr, .ndo_change_mtu = ip6_tnl_change_mtu, .ndo_get_stats64 = ip_tunnel_get_stats64, .ndo_get_iflink = ip6_tnl_get_iflink, }; #define GRE6_FEATURES (NETIF_F_SG | \ NETIF_F_FRAGLIST | \ NETIF_F_HIGHDMA | \ NETIF_F_HW_CSUM) static void ip6gre_tap_setup(struct net_device *dev) { ether_setup(dev); dev->netdev_ops = &ip6gre_tap_netdev_ops; dev->needs_free_netdev = true; dev->priv_destructor = ip6gre_dev_free; dev->features |= NETIF_F_NETNS_LOCAL; dev->priv_flags &= ~IFF_TX_SKB_SHARING; dev->priv_flags |= IFF_LIVE_ADDR_CHANGE; } static bool ip6gre_netlink_encap_parms(struct nlattr *data[], struct ip_tunnel_encap *ipencap) { bool ret = false; memset(ipencap, 0, sizeof(*ipencap)); if (!data) return ret; if (data[IFLA_GRE_ENCAP_TYPE]) { ret = true; ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]); } if (data[IFLA_GRE_ENCAP_FLAGS]) { ret = true; ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]); } if (data[IFLA_GRE_ENCAP_SPORT]) { ret = true; ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]); } if (data[IFLA_GRE_ENCAP_DPORT]) { ret = true; ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]); } return ret; } static int ip6gre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { struct ip6_tnl *nt; struct net *net = dev_net(dev); struct ip6gre_net *ign = net_generic(net, ip6gre_net_id); struct ip_tunnel_encap ipencap; int err; nt = netdev_priv(dev); if (ip6gre_netlink_encap_parms(data, &ipencap)) { int err = ip6_tnl_encap_setup(nt, &ipencap); if (err < 0) return err; } ip6gre_netlink_parms(data, &nt->parms); if (ip6gre_tunnel_find(net, &nt->parms, dev->type)) return -EEXIST; if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS]) eth_hw_addr_random(dev); nt->dev = dev; nt->net = dev_net(dev); ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]); dev->features |= GRE6_FEATURES; dev->hw_features |= GRE6_FEATURES; if (!(nt->parms.o_flags & TUNNEL_SEQ)) { /* TCP offload with GRE SEQ is not supported, nor * can we support 2 levels of outer headers requiring * an update. */ if (!(nt->parms.o_flags & TUNNEL_CSUM) || (nt->encap.type == TUNNEL_ENCAP_NONE)) { dev->features |= NETIF_F_GSO_SOFTWARE; dev->hw_features |= NETIF_F_GSO_SOFTWARE; } /* Can use a lockless transmit, unless we generate * output sequences */ dev->features |= NETIF_F_LLTX; } err = register_netdevice(dev); if (err) goto out; dev_hold(dev); ip6gre_tunnel_link(ign, nt); out: return err; } static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { struct ip6_tnl *t, *nt = netdev_priv(dev); struct net *net = nt->net; struct ip6gre_net *ign = net_generic(net, ip6gre_net_id); struct __ip6_tnl_parm p; struct ip_tunnel_encap ipencap; if (dev == ign->fb_tunnel_dev) return -EINVAL; if (ip6gre_netlink_encap_parms(data, &ipencap)) { int err = ip6_tnl_encap_setup(nt, &ipencap); if (err < 0) return err; } ip6gre_netlink_parms(data, &p); t = ip6gre_tunnel_locate(net, &p, 0); if (t) { if (t->dev != dev) return -EEXIST; } else { t = nt; } ip6gre_tunnel_unlink(ign, t); ip6gre_tnl_change(t, &p, !tb[IFLA_MTU]); ip6gre_tunnel_link(ign, t); return 0; } static void ip6gre_dellink(struct net_device *dev, struct list_head *head) { struct net *net = dev_net(dev); struct ip6gre_net *ign = net_generic(net, ip6gre_net_id); if (dev != ign->fb_tunnel_dev) unregister_netdevice_queue(dev, head); } static size_t ip6gre_get_size(const struct net_device *dev) { return /* IFLA_GRE_LINK */ nla_total_size(4) + /* IFLA_GRE_IFLAGS */ nla_total_size(2) + /* IFLA_GRE_OFLAGS */ nla_total_size(2) + /* IFLA_GRE_IKEY */ nla_total_size(4) + /* IFLA_GRE_OKEY */ nla_total_size(4) + /* IFLA_GRE_LOCAL */ nla_total_size(sizeof(struct in6_addr)) + /* IFLA_GRE_REMOTE */ nla_total_size(sizeof(struct in6_addr)) + /* IFLA_GRE_TTL */ nla_total_size(1) + /* IFLA_GRE_ENCAP_LIMIT */ nla_total_size(1) + /* IFLA_GRE_FLOWINFO */ nla_total_size(4) + /* IFLA_GRE_FLAGS */ nla_total_size(4) + /* IFLA_GRE_ENCAP_TYPE */ nla_total_size(2) + /* IFLA_GRE_ENCAP_FLAGS */ nla_total_size(2) + /* IFLA_GRE_ENCAP_SPORT */ nla_total_size(2) + /* IFLA_GRE_ENCAP_DPORT */ nla_total_size(2) + /* IFLA_GRE_FWMARK */ nla_total_size(4) + 0; } static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); struct __ip6_tnl_parm *p = &t->parms; if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || nla_put_be16(skb, IFLA_GRE_IFLAGS, gre_tnl_flags_to_gre_flags(p->i_flags)) || nla_put_be16(skb, IFLA_GRE_OFLAGS, gre_tnl_flags_to_gre_flags(p->o_flags)) || nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) || nla_put_in6_addr(skb, IFLA_GRE_REMOTE, &p->raddr) || nla_put_u8(skb, IFLA_GRE_TTL, p->hop_limit) || nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) || nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) || nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) || nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark)) goto nla_put_failure; if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE, t->encap.type) || nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT, t->encap.sport) || nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT, t->encap.dport) || nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS, t->encap.flags)) goto nla_put_failure; return 0; nla_put_failure: return -EMSGSIZE; } static const struct nla_policy ip6gre_policy[IFLA_GRE_MAX + 1] = { [IFLA_GRE_LINK] = { .type = NLA_U32 }, [IFLA_GRE_IFLAGS] = { .type = NLA_U16 }, [IFLA_GRE_OFLAGS] = { .type = NLA_U16 }, [IFLA_GRE_IKEY] = { .type = NLA_U32 }, [IFLA_GRE_OKEY] = { .type = NLA_U32 }, [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct ipv6hdr, saddr) }, [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct ipv6hdr, daddr) }, [IFLA_GRE_TTL] = { .type = NLA_U8 }, [IFLA_GRE_ENCAP_LIMIT] = { .type = NLA_U8 }, [IFLA_GRE_FLOWINFO] = { .type = NLA_U32 }, [IFLA_GRE_FLAGS] = { .type = NLA_U32 }, [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 }, [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 }, [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 }, [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 }, [IFLA_GRE_FWMARK] = { .type = NLA_U32 }, }; static struct rtnl_link_ops ip6gre_link_ops __read_mostly = { .kind = "ip6gre", .maxtype = IFLA_GRE_MAX, .policy = ip6gre_policy, .priv_size = sizeof(struct ip6_tnl), .setup = ip6gre_tunnel_setup, .validate = ip6gre_tunnel_validate, .newlink = ip6gre_newlink, .changelink = ip6gre_changelink, .dellink = ip6gre_dellink, .get_size = ip6gre_get_size, .fill_info = ip6gre_fill_info, .get_link_net = ip6_tnl_get_link_net, }; static struct rtnl_link_ops ip6gre_tap_ops __read_mostly = { .kind = "ip6gretap", .maxtype = IFLA_GRE_MAX, .policy = ip6gre_policy, .priv_size = sizeof(struct ip6_tnl), .setup = ip6gre_tap_setup, .validate = ip6gre_tap_validate, .newlink = ip6gre_newlink, .changelink = ip6gre_changelink, .get_size = ip6gre_get_size, .fill_info = ip6gre_fill_info, .get_link_net = ip6_tnl_get_link_net, }; /* * And now the modules code and kernel interface. */ static int __init ip6gre_init(void) { int err; pr_info("GRE over IPv6 tunneling driver\n"); err = register_pernet_device(&ip6gre_net_ops); if (err < 0) return err; err = inet6_add_protocol(&ip6gre_protocol, IPPROTO_GRE); if (err < 0) { pr_info("%s: can't add protocol\n", __func__); goto add_proto_failed; } err = rtnl_link_register(&ip6gre_link_ops); if (err < 0) goto rtnl_link_failed; err = rtnl_link_register(&ip6gre_tap_ops); if (err < 0) goto tap_ops_failed; out: return err; tap_ops_failed: rtnl_link_unregister(&ip6gre_link_ops); rtnl_link_failed: inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE); add_proto_failed: unregister_pernet_device(&ip6gre_net_ops); goto out; } static void __exit ip6gre_fini(void) { rtnl_link_unregister(&ip6gre_tap_ops); rtnl_link_unregister(&ip6gre_link_ops); inet6_del_protocol(&ip6gre_protocol, IPPROTO_GRE); unregister_pernet_device(&ip6gre_net_ops); } module_init(ip6gre_init); module_exit(ip6gre_fini); MODULE_LICENSE("GPL"); MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)"); MODULE_DESCRIPTION("GRE over IPv6 tunneling device"); MODULE_ALIAS_RTNL_LINK("ip6gre"); MODULE_ALIAS_RTNL_LINK("ip6gretap"); MODULE_ALIAS_NETDEV("ip6gre0");